Code Contracts at runtime

Question

As far as I read in a nutshell book, code contracts could degrade the runtime performance.

Is it possible to disable code contracts in production?

Answer 1

The user manual explains this in a fair amount of detail - there are all kinds of options you can have. Each build configuration can have different settings for which contracts are checked at execution time, and it's not an "all or nothing" choice - you can enforce all, some or none of the contracts, based on settings which can be tweaked in Visual Studio.

Answer 2

I have my favorite options described on my blog.

To summarize:

• In Release mode, I recommend unchecking Perform Runtime Contract Checking but selecting to Build the Contract Reference Assembly. This will place Preconditions in a separate dll which your clients can optionally use (if they check Call-site Requires Checking), but removes all overhead if they don't check that option.
• In Debug mode, set Perform Runtime Contract Checking to Full.

Some people prefer Preconditions to be included in their Release build. This is particularly useful if distributing via NuGet because they don't support Code Contract dlls. For my NuGet packages, I'm migrating towards including Preconditions in the Release builds, but also having a separate download for a "Release without Preconditions" build.